Optical trapping of gold nanoparticles by cylindrical vector beam.

Optical trapping of gold nanoparticles is experimentally demonstrated using radially and azimuthally polarized beams. The transverse optical trapping stiffness of gold nanoparticles is measured. The radially polarized beam exhibits a higher trapping efficiency than the azimuthally polarized beam and the Gaussian beam. The transverse stiffness of particles with different diameters is measured experimentally and calculated via the discrete-dipole approximation method, and good agreement between theory and experiment is found.